1. Technical Field
The present invention relates to an optical device with a zoom lens and, particularly, to a zoom ratio adjusting switch.
2. Description of Related Art
Various types of compact cameras equipped with zoom lenses have been put on the market. Motor driven compact cameras of this kind are equipped with a zoom ratio adjusting switch for actuating an electric motor to drive the zoom lens to adjust a zoom ratio.
One conventional zoom ratio adjusting switch comprises a camera panel and a rotary member. The panel defines three arc-shaped and elongated grooves therethrough, which are uniformly arranged in the panel, adjoining an outermost portion of a round region of the panel. The rotary member comprises a base attached to a side of the round region of the panel, and three elastic fingers extending perpendicularly from the base. The elastic fingers respectively elastically extend through the grooves and grasp an opposite side of the round region of the panel, to thereby secure the rotary member to the panel. The elastic fingers can slide in the grooves along a circumferential direction of the round region of the panel. Thus, the rotary member is kept in a neutral position until acted on by a force to rotate between a tele-angle end position and a wide-angle end position. Specifically, the electric motor rotates in one direction to shift the zoom lens toward the telephoto side while the rotary member is turned toward the tele-angle end position, and rotates in a reverse direction to shift the zoom lens toward the wide-angle end while the rotary member is turned to the wide-angle end position.
In order to firmly secure the rotary member to the panel, a diameter of the round region of the panel must be slightly larger than a diameter of a circle defined by innermost extremities of the elastic fingers. The elastic fingers must be expanded outwardly to extend through the grooves in the panel, and then rebound to grasp said opposite side of the round region of the panel. However, the elastic fingers are slim and at risk of being broken due to excessive force or deformation. As a result, the zoom ratio adjusting switch is unreliable.
What is needed, therefore, is a zoom ratio adjusting switch which is reliable and durable.